What is an approved animal drug?

An approved animal drug has gone through FDA’s drug approval process. During this process, the agency reviews information, submitted by the drug company, about the animal drug. If the information meets the requirements for approval, the agency approves the animal drug. FDA’s approval means the drug is safe and effective when it’s used according to the label. FDA’s approval also ensures that the drug’s strength, quality, and purity are consistent from batch to batch, and that the drug’s label is truthful and complete.

How does an animal drug get approved by FDA?

The approval process for an animal drug is a collaborative effort between the drug company and FDA. In a nutshell, the steps of the approval process are:

The drug company collects information about the safety and effectiveness of a new animal drug. The company may need to conduct studies to get this information. For any studies that are performed, the company analyzes the results.

Based on the collected information, including any study results, the drug company decides if there is enough proof that the drug meets the requirements for approval. The company must prove that the drug is safe and effective for a specific use in a specific animal species. If the drug is for food-producing animals (like cows or chickens), the company must also prove that it’s safe for people to eat food from treated animals, such as meat, milk, and eggs.

If the drug company decides the drug meets the requirements for approval, the company submits a New Animal Drug Application to FDA. (For a generic animal drug, it’s called an Abbreviated New Animal Drug Application.) The application includes all the information about the drug and the proposed label.

A team of FDA personnel, including veterinarians, animal scientists, biostatisticians, chemists, microbiologists, pharmacologists, and toxicologists, reviews the application. If the agency’s team agrees with the company’s conclusion that the drug is safe and effective if it’s used according to the proposed label, FDA approves the drug and the drug company can legally sell it.

What are the benefits of FDA’s drug approval process?

The benefit of FDA’s drug approval process is the assurance that an approved animal drug is safe, effective, and high-quality. The drug company has shown that the drug is safe and effective in a specific animal species when used according to the label. The label is written specifically for that species and includes all necessary information to use the drug safety and effectively, including the risks associated with the drug. The drug company has also shown that the manufacturing process consistently produces a high-quality drug.

Another benefit of the drug approval process is FDA’s continued monitoring of approved animal drugs after they’re on the market. Sometimes, the agency’s post-approval monitoring uncovers safety and effectiveness issues that were unknown at the time of approval. FDA also continues to monitor the drug’s labeling, the drug’s manufacturing process, and the company’s marketing communications related to the drug.

Are approved animal drugs the only drugs that can be legally used in animals?

Besides approved animal drugs, there are two other categories of legally marketed animal drugs that can be used in animals, depending on the situation. These two categories are: (1) conditionally approved animal drugs; and (2) indexed animal drugs. Only drugs for minor species or for a minor use in a major species can be conditionally approved and only drugs for certain minor species can be indexed.

FDA classifies horses, dogs, cats, cattle, pigs, chickens, and turkeys as the seven major species. All other animals, such as sheep, goats, and hamsters, are minor species. A minor use in a major species is the use of a drug in a major species for a condition that occurs:

Infrequently and in only a small number of animals each year; or

In a limited geographic area and in only a small number of animals each year.

For example, the use of a drug to control pain in dogs with bone cancer is a minor use in a major species because relatively few dogs get bone cancer each year.

Conditional Approval

A conditionally approved animal drug has gone through FDA’s drug approval process except the drug has not yet met the effectiveness standard for full approval. FDA’s conditional approval means that when used according to the label, the drug is safe and has a “reasonable expectation of effectiveness.”

The conditional approval is valid for one year. The drug company can ask FDA to renew the conditional approval annually for up to four more years, for a total of five years of conditional approval. During the 5-year period, the drug company can legally sell the animal drug while collecting the remaining effectiveness data. This early marketing is good for two reasons: first, the drug is available sooner to be used in animals that may benefit from it; and second, the company can recoup some of the investment costs while completing the full approval.

After collecting the remaining effectiveness data, the company then submits a New Animal Drug Application to FDA for full approval. FDA reviews the application and, if appropriate, fully approves the drug.

Non-food-producing minor species, such as ornamental fish, ferrets, and pet birds. These animals are typically not eaten by people or by other animals that produce food for people to eat; and

An early non-food life stage of a food-producing minor species, such as oyster spat (immature oysters). Because people don’t generally eat oyster spat, a drug to treat a disease in spat can be indexed, but a drug to treat a disease in adult oysters, which people commonly eat, can’t be indexed.

Indexing a drug is quite different from the drug approval process. Indexing relies heavily on a panel of qualified experts outside FDA. The experts review the drug’s safety in the specific minor species and the drug’s effectiveness for the intended use. All experts on the panel must agree that, when used according to the label, the drug’s benefits outweigh the risks to the treated animal. If FDA agrees with the panel, the agency adds the drug to the Index.

Ask your veterinarian

Look up the drug in Animal Drugs @ FDA

Animal Drugs @ FDA is an online database that includes most FDA-approved and conditionally approved animal drugs. You can search this database in several ways, such as by the drug’s proprietary name (also known as the trade name or brand name) or active ingredient. Indexed animal drugs aren’t listed in Animal Drugs @ FDA.

Read the Client Information Sheet

Some approved animal drugs have a Client Information Sheet written specifically for pet owners in a user-friendly, question-and-answer format. The handout gives you detailed information about your pet’s medication and the side effects it can cause, helping you use the medication as safely and effectively as possible for your pet. You can get a Client Information Sheet from your veterinarian.

Not all approved animal drugs have Client Information Sheets available. Generally, they’re written for medications where owner involvement is important for safe and effective use.

Look up the drug’s label

You can also find drug information by searching for the label in one of two online databases: the FDA Online Label Repository and DailyMed, a website run by the National Library of Medicine. You can search both databases in several ways, such as by the drug’s proprietary name or active ingredient.

Look up the drug in the Index

Read the drug’s Freedom of Information Summary

Every approved, conditionally approved, and indexed animal drug has a Freedom of Information (FOI) Summary. This summary is a public document describing the safety and effectiveness information that supports the agency’s decision to approve, conditionally approve, or index the animal drug. The document includes summaries of studies that were done and explains the basis for the agency’s decision. Links to the FOI Summaries for animal drugs can be found in Animal Drugs @ FDA and on the Index of Legally Marketed Unapproved New Animal Drugs for Minor Species.

My dog had a bad reaction to a drug. How do I report this side effect?

FDA encourages pet owners to work with their veterinarian to report problems with any animal drug. Problems include undesired side effects associated with a drug and product defects. Undesired side effects are called adverse drug experiences. Adverse drug experiences also include a lack of effectiveness (the drug doesn’t do what it’s supposed to do) and unfavorable reactions in people who handle the drug. Product defects are problems such as defective packaging or the drug has an abnormal appearance.

By reporting undesired side effects and product defects with animal drugs, you help FDA more easily identify and correct problems.

How does FDA get an unsafe or ineffective animal drug off the market?

Under federal law, FDA has the authority to remove an approved, conditionally approved, or indexed animal drug from the market if the agency later finds the drug to be unsafe or ineffective.

The agency follows specific regulations and policies for removing an approved animal drug from the market. In most cases when FDA withdraws the approval for an animal drug, it’s at the request of the drug company because the company no longer manufactures or markets the drug.

If FDA finds that a conditionally approved drug is unsafe, the agency can deny the company’s request for an annual renewal. (Remember, a conditional approval is valid for only one year. To legally sell the drug after one year, the drug company must ask FDA for an annual renewal. The company can receive up to four annual renewals, for a total of five years of conditional approval.) Under certain conditions, the agency can also remove a conditionally approved animal drug from the market outside of the annual renewal process.

If FDA finds that an indexed animal drug is unsafe or ineffective, the agency removes the drug from the Index and the drug company can no longer legally sell it.

Is a generic animal drug as safe and effective as the brand name animal drug?

Yes. FDA requires a generic drug to have the same quality, performance, and intended uses as the already-approved brand name drug. The generic drug must be bioequivalent to the approved brand name drug. This means that the generic drug is absorbed by and performs the same way in the animal’s body as the brand name drug.

FDA also requires that the generic drug be manufactured under the same strict manufacturing standards as the brand name drug. The manufacturing process for the generic drug must consistently produce a product that is equivalent to the brand name animal drug in identity, strength, purity, and quality.

What are the differences between an over-the-counter animal drug, a prescription animal drug, and a veterinary feed directive animal drug?

One difference between these three categories of animal drugs is whether FDA has determined that veterinary oversight is required for the safe and effective use of the drug. If the agency determines that adequate “directions for use” can be written on the drug’s label in such a way that a non-veterinarian can use the drug safely and effectively, then the drug company can market the animal drug as over-the-counter (OTC). If not, then the drug company must market the animal drug as either prescription (Rx) or veterinary feed directive (VFD).

Both Rx and VFD drugs require veterinary oversight to be used safely and effectively. The main difference between these two categories of animal drugs is whether the drug is used in or on animal feed. When the drug is for use in or on animal feed (a medicated feed), FDA approves it as a VFD drug. When the drug is not for use in or on animal feed, FDA approves it as a prescription drug. Federal law makes it clear that VFD drugs are not prescription drugs. A VFD drug requires veterinary oversight without invoking state pharmacy laws for a prescription drug that are unworkable for medicated feed.

A prescription animal drug can be dispensed only by or on the lawful written order of a licensed veterinarian and must have the following statement on the label:

"Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian."

A VFD is a written order issued by a licensed veterinarian in the course of the veterinarian’s professional practice that authorizes the client (the owner or other animal caretaker) to obtain and use a VFD drug in or on animal feed. A VFD animal drug must have the following statement on the label:

‘‘Caution: Federal law restricts medicated feed containing this veterinary feed directive (VFD) drug to use by or on the order of a licensed veterinarian.’’

Is it safe to give my pet a pain reliever for people, such as aspirin, ibuprofen, naproxen, or acetaminophen?

When you see your dog or cat limping or showing other signs of pain, it’s common to think about giving him or her an over-the-counter pain reliever for people. But a pain reliever for people isn’t a good alternative to a pain reliever approved for animals.

Even if data show that a non-steroidal anti-inflammatory drug (NSAID), like aspirin, ibuprofen, and naproxen, is safe and effective in people, the drug may not be safe and effective in dogs because the drug may:

Last longer;

Have a higher absorption rate in the stomach and small intestine; and

Reach higher blood levels.

These differences may lead to toxic effects in dogs, such as stomach problems as well as liver and kidney damage.

You have to be even more careful with cats. Cats are more sensitive than dogs to the side effects of NSAIDs because they aren’t able to break down the drugs as well.

Acetaminophen (brand name Tylenol) is not an NSAID and doesn’t have much anti-inflammatory activity. Acetaminophen is fatal to cats. Cats should never be given acetaminophen because their liver cannot safely break down the drug.

Even if your pet seems painful, don’t give him or her anything in your medicine cabinet until you talk to your veterinarian.

Why does a veterinarian have to examine my pet before prescribing a drug?

Many states have laws governing the practice of veterinary medicine, and these laws may require a veterinarian to have a valid relationship with both the patient and the client before he or she can prescribe a drug for an animal. Depending on the state, such a relationship may include a physical examination. Your veterinarian is the best person to determine which drug is best for your pet’s condition and to make sure it’s used appropriately. For more information about the veterinary medicine practice laws in your state, contact your state’s veterinary medical board:

What is a “veterinarian-client-patient relationship”?

The federal definition of a veterinarian-client-patient relationship (VCPR) has three parts:

The veterinarian has assumed responsibility for making medical judgments about the health of an animal or animals and the need for medical treatment. In turn, the client (the owner or other animal caretaker) has agreed to follow the veterinarian’s instructions;

The veterinarian has sufficient knowledge of the animal or animals to develop a general or preliminary diagnosis of the medical condition; and

The veterinarian is readily available for follow-up in case of undesired side effects or the treatment doesn’t work. Such a relationship can exist only when a veterinarian has recently seen and is personally acquainted with the keeping and care of the animal or animals. This means a veterinarian has recently examined the animal or animals, made “medically appropriate and timely visits” to the premises, or done both.

For a veterinarian to legally prescribe a drug for an extra-label use, it must be done within the context of a valid VCPR that, at a minimum, meets the three requirements described above. States may have additional requirements for a valid VCPR and the definition may vary by state.

I have leftover medication for my pet. How should I get rid of it?

Get rid of expired, unused, or unwanted medications properly. Pets, especially dogs, are known to go dumpster-diving and get into the garbage, so follow these guidelines for throwing out medications in your household trash:

Mix medications (do NOT crush tablets or capsules) with a substance that doesn’t taste good, such as cat litter or used coffee grounds;

Place the mixture in a sealable container, such as a zip-top plastic bag; and

Community-based drug “take-back” programs offer the best solution for disposing of expired, unused, or unwanted medications. The same take-back programs available for people medications will also take back pet medications.

For more information about how to safely dispose of expired, unused, or unwanted medications for both people and pets, please see:

Some pets need a medication that requires you to use “sharps” at home. “Sharps” are medical devices with sharp points or edges that can puncture or cut skin, such as needles and syringes. For example, insulin—a medication used to treat diabetes in dogs and cats—is injected under the skin using a small insulin syringe that has a needle.

For more information about how to safely dispose of used sharps, please see:

How does FDA evaluate the impact of an animal drug on the environment?

Under the National Environmental Policy Act, FDA must consider how the environment will be affected if the agency approves, conditionally approves, or indexes an animal drug. To do this, the agency requires the drug company to prepare an Environmental Assessment (EA). This assessment describes how much drug is expected to get into the environment and its potential environmental effects.

If FDA decides that the drug will not significantly impact the environment based on the information in the EA, the agency writes what’s called a “Finding of No Significant Impact.” If FDA decides that the drug will significantly impact the environment, the agency writes an Environmental Impact Statement.

A drug company can ask FDA for a “categorical exclusion," or “CE” for short. A CE means that the drug falls into a legally-defined category that’s unlikely to affect the environment. If the agency grants a CE, the company doesn’t have to prepare an EA.

Two examples of when the agency typically grants a CE are:

A drug for companion animals, like cats and dogs. Because a drug for companion animals is given to one animal at a time (as opposed to a herd or flock of animals), not much of the drug is likely to get into the environment; and

A slight change to an already-approved animal drug if the change will not increase how much drug is used or how much will get into the environment.